A warmer world is a sicker world
When people talk about climate change, the topics that come up first are hurricanes, floods, melting glaciers, polar bears. Rarely does the conversation turn to heart disease or premature births. But it should.
Climate change is a public health emergency. The past several years have seen a surge of concern from the health community regarding lives lost due to the warming climate and the pollution that causes it.
The disruption of the climate threatens health in many ways, but the most direct impact is from extreme heat. In a report entitled "Killer Heat in the United States: Climate Choices and the Future of Dangerously Hot Days," researchers from the Union of Concerned Scientists used projected temperatures and humidity from multiple climate models to estimate the number of dangerous heat days we can expect in the future.
During the 30-year period from 1971-2000, the Chicago area had an average of one day per year with a heat index above 105 degrees. With no action to reduce emissions, we can expect 14 days a year at or above this level by midcentury, and by the end of the century, 34 days.
What are the health implications of more frequent heat waves?
• Extreme heat places extra stress on the heart as blood vessels dilate in order to dissipate the excess heat. Older people's blood vessels are less able to dilate, making them especially vulnerable to overheating.
• Pregnant women are more likely to go into premature labor during heat waves, as dehydration during pregnancy can reduce blood flow to the uterus.
• Dehydration during pregnancy can also reduce blood flow to the placenta, which can lead to fetal nutrition deficiencies and low birth weight.
• When body temperatures rise to extreme levels, damage can occur to the brain, heart, lungs, kidneys and liver.
• Loss of electrolytes from dehydration increases the risk of kidney failure and heart failure.
• Athletes, used to pushing themselves to the limit of their physical abilities, may continue pushing even though they feel ill, sometimes with fatal consequences. The Illinois High School Association instituted a new Fall Sports Heat Acclimatization Policy this year restricting practices and competition during excessive heat.
• Babies and young children are less able to regulate their body temperatures and are especially vulnerable.
• Recent research suggests that higher temperatures may lead to a substantial increase in new cases of diabetes. It appears that we are more glucose intolerant in hotter weather.
These are some of the reasons that the American Medical Association, the American Heart Association, and the American Lung Association have joined with over 70 other major medical and public health groups to declare climate change a "true public health emergency."
"On Climate, Health, and Equity: A Policy Action Agenda," released in June, calls on elected officials to act now: "The health, safety and well-being of millions of people in the U.S. have already been harmed by human-caused climate change, and health risks in the future are dire without urgent action to fight climate change."
The medical community will need to increase their efforts to address the human suffering caused by climate change. It is also necessary to get to the root cause. The UCS study projects that bold action to reduce emissions now will reduce the annual number of dangerous heat days the Chicago area sees in the future from a little over a month to a little over a week. A co-benefit: reducing fossil fuel emissions will immediately make the air we breathe cleaner.
We urge everyone, whether in the medical profession or not, to contact your members of Congress. Tell them that a warming climate is harming human health now. Tell them that you want them to pass legislation that drives down emissions fast. Tell them there is no time to waste.
Dr. Lori Byron, M.D., and Terry Quain are volunteers with Citizens' Climate Lobby. Byron is co-chair of CCL's national Health Action Team. Quain chairs the Greater Naperville Area Chapter of CCL.